Magnetospheric Multiscale (MMS)

Scientist John Dorelli explains the MMS mission's orbit and why the four spacecraft fly in a tetrahedron formation.

On its journey, MMS will observe a little-understood, but universal phenomenon called magnetic reconnection, responsible for dramatic re-shaping of the magnetic environment near Earth, often sending intense amounts of energy and fast-moving particles off in a new direction. Not only is this a fundamental physical process that occurs throughout the universe, it is also one of the drivers of space weather events at Earth. To truly understanding the process, requires four identical spacecraft to track how such reconnection events move across and through any given space in 3D.

NASA Administrator Charles Bolden had a firsthand look at work being done on the Magnetospheric Multiscale (MMS) spacecraft during a visit to the agency's Goddard Space Flight Center in Greenbelt, Maryland, on Monday, May 12, 2014. Bolden visited Goddard's Integration and Test Facility where the four MMS spacecraft are undergoing testing. The spacecraft were in a rare four-stack arrangement inside a clean room after completing vibration testing. The clean room itself was temporarily altered to allow a close-up view of the approximate 20-foot high collection of four observatories in their launch configuration. In addition to Bolden, MMS project personnel were available to answer questions about the mission, ground testing and preps for launch. During its two-year mission, MMS will explore the mystery of how magnetic fields around Earth connect and disconnect, explosively releasing energy — a process known as magnetic reconnection. The four MMS spacecraft will provide the first three-dimensional views of this fundamental process that occurs throughout our universe.

In March 2015, NASA will launch four identical spacecraft to study how magnetic fields around Earth connect and disconnect, explosively releasing energy – a process known as magnetic reconnection. The Magnetospheric Multiscale, or MMS, mission will provide the first three-dimensional views of this fundamental process that can accelerate particles to nearly the speed of light. MMS uses Earth’s protective magnetic space environment, the magnetosphere, as a natural laboratory to directly measure reconnection. Reconnection is a common processes in our universe; occurring in space near Earth, in the atmosphere of the sun and other stars, in the vicinity of black holes and neutron stars, and at virtually any boundary between space plasmas, including the boundary between our solar system's heliosphere and interstellar space.

Taking advantage of an unprecedented alignment of eight satellites through the vast magnetic environment that surrounds Earth in space, including NASA's ARTEMIS and THEMIS, scientists now have comprehensive details of the energy's journey through a process that forms the aurora, called a substorm. Their results showed that small events unfolding over the course of a millisecond can result in energy flows that last up to half an hour and cover an area 10 times larger than Earth.

Trying to understand how gigantic explosions on the sun can create space weather effects involves tracking energy from the original event all the way to Earth. It's not unlike keeping tabs on a character in a play with many costume changes, because the energy changes form frequently along its journey: magnetic energy causes eruptions that lead to kinetic energy as particles hurtle away, or thermal energy as the particles heat up. Near Earth, the energy can change through all these various forms once again.

Most of the large and small features of substorms take place largely in the portion of Earth's magnetic environment called the magnetotail. Earth sits inside a large magnetic bubble called the magnetosphere. As Earth orbits around the sun, the solar wind from the sun streams past the bubble, stretching it outward into a teardrop. The magnetotail is the long point of the teardrop trailing out to more than 1 million miles on the night side of Earth. The moon orbits Earth much closer, some 240,000 miles away, crossing in and out of the magnetotail.

Mathematical models of Earth's magnetosphere have become increasingly more complex and accurate. They have sufficient detail to illustrate many small-scale phenomena. In this simulation run of the Geospace General Circulation Model (GGCM) we see new details that have been observed by in situ satellites. As the solar wind is deflected around Earth's magnetosphere (the 'bubble' of plasma surrounding Earth held by Earth's magnetic field), plasma flows within the bubble can change. In the graphics below, physical variables such as magnetic field and electric currents are plotted. With these variables, we overlay the net flow of the plasma (arrows), subjected to selection criteria to separate flows of plasma away from Earth and towards Earth. Green arrows are low-speed flows (below about 150 kilometers/second), while red arrows correspond to high-speed plasmal flows (about 300 kilometers/second and higher).

This movie takes us on a space weather journey from the center of the sun to solar eruptions in the sun's atmosphere all the way to the effects of that activity near Earth. The view starts in the core of the sun where atoms fuse together to create light and energy. Next we travel toward the sun's surface, watching loops of magnetic fields rise up to break through the sun's atmosphere, the corona. In the corona is where we witness giant bursts of radiation and energy known as solar flares, as well as gigantic eruptions of solar material called coronal mass ejections or CMEs. The movie follows one of these CME's toward Earth where it impacts and compresses Earth's own protective magnetic bubble, the magnetosphere. As energy and particles from the sun funnel along magnetic field lines near Earth, they ultimately produce aurora at Earth's poles.

This is an update to an older magnetic reconnection animation (10072). The ionized wind from the Sun generates reconnection in the Earth's magnetic field. Particles leak in from the rediation belts producing the auroras.

The IMAGE and Cluster spacecraft were ideally positioned in their orbits to view the reconnection event which led to the proton aurora formation.

The Far Ultraviolet camera aboard the IMAGE spacecraft captured this view of a proton aurora (the bright spot near the center of the view) as well as the ring of the electron aurora. The protons for this aurora came from the incoming solar wind. They made it though the Earth's magnetic shield in a magnetic reconnection event higher in the magnetosphere which was detected by the Cluster satellite. Note: A 'corner' appears in the data in the beginning as the IMAGE spacecraft moves into a position where it can view the entire north polar region.

Two NASA spacecraft have provided the most comprehensive movie ever of a mysterious process at the heart of all explosions on the sun: magnetic reconnection.

Magnetic reconnection happens when magnetic field lines come together, break apart, and then exchange partners, snapping into new positions and releasing a jolt of magnetic energy. This process lies at the heart of giant explosions on the sun such as solar flares and coronal mass ejections, which can fling radiation and particles across the solar system.

Magnetic field lines, themselves, are invisible, but the sun's charged plasma particles course along their length. Space telescopes can see that material appearing as bright lines looping and arcing through the sun’s atmosphere, and so map out the presence of magnetic field lines.

Looking at a series of images from the Solar Dynamics Observatory (SDO), scientists saw two bundles of field lines move toward each other, meet briefly to form what appeared to be an “X” and then shoot apart with one set of lines and its attendant particles leaping into space and one set falling back down onto the sun.

To confirm what they were seeing, the scientists turned to a second NASA spacecraft, the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). RHESSI collects spectrograms, a kind of data that can show where exceptionally hot material is present in any given event on the sun. RHESSI showed hot pockets of solar material forming above and below the reconnection point, an established signature of such an event. By combining the SDO and RHESSI data, the scientists were able to describe the process of what they were seeing, largely confirming previous models and theories, while revealing new, three-dimensional aspects of the process.

Magnetic reconnection is one of the most important processes in the space. Reconnection occurs when crossed magnetic field lines snap, explosively flinging away nearby particles at high speeds. The following animations illustrate this magnetic explosion on the Sun, near black holes, around Earth.

In March of 2015, an unprecedented NASA mission will launch to study a process so mysterious that no one has ever directly measured it in action. To create the first-ever 3-dimensional maps of this process, a process called magnetic reconnection, which occurs all over the universe, the Magnetospheric Multiscale, or MMS, mission uses four separate spacecraft equipped with ultra high speed instruments.

Launching four satellites into space simultaneously is a complicated process. In addition, each spacecraft has six booms that will unfold and extend in space once in orbit. A launch and deployment with so many moving parts must be meticulously planned.

Watch the video to get a sneak preview of how MMS will make this journey: The four spacecraft are housed in a single rocket on their trip into space. One by one, each ejects out, before moving into a giant pyramid-shaped configuration. Next each spacecraft deploys its six booms.

Once in orbit, MMS will fly through regions near Earth where this little-understood process of magnetic reconnection occurs. Magnetic reconnection happens in thin layers just miles thick, but can tap into enough power at times to create gigantic explosions many times the size of Earth.

Reconnection happens when magnetic field lines explosively realign and release massive bursts of energy, while hurling particles out at nearly the speed of light in all directions. Magnetic reconnection powers eruptions on the sun and – closer to home – triggers the flow of material and energy from interplanetary space into near-Earth space. The MMS orbit will carry the four spacecraft through reconnection regions near Earth, using this nearby natural laboratory to better understand how reconnection occurs everywhere in space.

For more information about MMS, visit: www.nasa.gov/mms

The Magnetospheric Multiscale (MMS) mission is a Solar Terrestrial Probes mission comprising four identically instrumented spacecraft that will use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration, and turbulence. These processes occur in all astrophysical plasma systems but can be studied in situ only in our solar system and most efficiently only in Earth’s magnetosphere, where they control the dynamics of the geospace environment and play an important role in the processes known as “space weather.”

Learn more about MMS at www.nasa.gov/mms

This animation follows Magnetosphere Multiscale(MMS) Mission from launch at Kennedy Space Center through deployment and on station doing science. The MMS mission is comprising four identically instrumented spacecraft that will use Earth’s magnetosphere as a laboratory to study the microphysics of three fundamental plasma processes: magnetic reconnection, energetic particle acceleration, and turbulence.

This animation show the MMS spacecraft transiting through a reconnection event on the front side of Earth.

This visualization was created in support of the MMS Preliminary Design Review (PDR) which was held May 4 - 7, 2009.

This visualization was created in support of the MMS Preliminary Design Review (PDR) which was held May 4th through May 7th of 2009.